get_next_line/scratch/get_next_line.c

/* ************************************************************************** */
/*                                                                            */
/*                                                        :::      ::::::::   */
/*   get_next_line.c                                    :+:      :+:    :+:   */
/*                                                    +:+ +:+         +:+     */
/*   By: whaffman <whaffman@student.codam.nl>       +#+  +:+       +#+        */
/*                                                +#+#+#+#+#+   +#+           */
/*   Created: 2024/07/11 17:35:46 by whaffman          #+#    #+#             */
/*   Updated: 2024/07/12 10:18:44 by whaffman         ###   ########.fr       */
/*                                                                            */
/* ************************************************************************** */

#include "get_next_line.h"
#include <fcntl.h>

size_t	ft_strlen(const char *s)
{
	size_t	length;

	length = 0;
	while (*s++)
		length++;
	return (length);
}

char	*ft_strchr(const char *str, int c)
{
	while (*str)
	{
		if (*str == c)
			return ((char *) str);
		str++;
	}
	if (*str == c)
		return ((char *) str);
	return (NULL);
}

void	ft_lstclear(t_list **lst, void (*del)(void *))
{
	t_list	*next;

	if (!del || !lst)
		return ;
	while (*lst)
	{
		if ((*lst)->next)
			next = (*lst)->next;
		else
			next = NULL;
		del((*lst)->content);
		free(*lst);
		*lst = next;
	}
}

t_list *new_node(size_t size)
{
	t_list	*node;
	char	*buffer;
	
	if (size <= 0)
		return (NULL);
	buffer = malloc(size * sizeof(char));
	if (!buffer)
		return (NULL);
	node = malloc(sizeof(t_list));
	if (!node)
	{
		free(buffer);
		return (NULL);
	}
	node->content = buffer;
	node->next = NULL;
	return (node);
}

int	read_block(int fd, t_list **stock)
{
	t_list	*node;
	int		read_result;

	if (fd < 0)
		return (-1);
	node = new_node(BUFFER_SIZE + 1);
	if (!node)
		return (-1);
	read_result = read(fd, node->content, BUFFER_SIZE);
	if (read_result > 0)
	{
		(node->content)[read_result] = '\0';
		node->next = NULL;
		*stock = node;
	}
	return (read_result);
}

int restock(int fd, t_list **stock)
{
	int read_result;
	t_list *last_node = *stock;

	// Find the last node in the list
	while (last_node && last_node->next)
		last_node = last_node->next;

	// Read blocks until a newline or EOF is reached
	while (1)
	{
		read_result = read_block(fd, &last_node);
		if (read_result < 0)
			return -1;
		if (read_result == 0 || ft_strchr(last_node->content, '\n'))
			break;
		last_node = last_node->next;
	}

	return read_result;
}

size_t	len_till_newline(t_list *lst)
{
	size_t	len;
	size_t	i;

	len = 0;
	while(lst)
	{
		i = 0;
		while (lst->content[i] && lst->content[i] != '\n')
		{
			len++;
			i++;
		}
		if (lst->content[i] == '\n')
			return (len + 1);
		lst = lst->next;
	}
	return (len);
}

char *get_line(t_list *lst)
{
	size_t	i;
	size_t	j;
	size_t	len;
	char	*line;
	
	len = len_till_newline(lst);
	line = malloc((len + 1) * sizeof(char));
	if (!line)
		return (NULL);
	i = 0;
	while (i < len && lst)
	{
		j = 0;
		while(lst->content[j])
		{
			line[i + j] = (char) lst->content[j];
			j++;
		}
		i += j;
		lst = lst->next;
	}
	line[i] = '\0';
	return (line);
}

void	clean_lst(t_list **lst)
{	
	t_list	*last;
	t_list	*new;
	size_t	i;
	size_t	j;

	last = *lst;
	while(last->next)
		last = last->next;
	i = 0;
	while(last->content[i] && last->content[i] != '\n')
		i++;
	if (!last->content[i])
	{
		new = new_node(ft_strlen(&(last->content[i++])) + 1);
		if (!new)
			return ;
		j = 0;
		while (last->content[i + j])
		{
			new->content[j] = last->content[i + j];
			j++;
		}
		ft_lstclear(lst, free);
		*lst = new;
	}
}

char	*get_next_line(int fd)
{
	static t_list	*stock;
	char *line;

	if (fd < 0)
		return (NULL);
	restock(fd, &stock);
	if (!stock)
		return (NULL);
	line = get_line(stock);
	clean_lst(&stock);	
	return (line);
}


#include <stdio.h>

int main(int argc, char **argv)
{
	int fd;
	char *line;

	if (argc > 1)
		fd = open(argv[1], O_RDONLY);
	else
		fd = STDIN_FILENO;

	if (fd < 0)
	{
		return 1;
	}

	while ((line = get_next_line(fd)) != NULL)
	{
		printf("%s\n", line);
		free(line);
	}

	close(fd);

	return 0;
}